Which variable(s) in the data set are measured using a ordinal scale?

Age Group and Heart Rate

Age Group

Environment

Environment and Age Group

The system of equations graphed below has how many solutions?

Expresa commuter train leaves downtown sation and travels at a average speed of 55 miles per hour towards the north side sation, which is 50miles away. thirty minutes later, express commuter train #7 leaves north side and travels at a average speed of 35miles per hour towards downtown sation. at the moment the two trains pass each other, how far(in miles) is train #12 from the downtown sation and how long(in minutes) has the #12 train been traveling

Write the equation of the circle centered at (10,-2) with radius 2.